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UNITED STATES PATENT OFFICE.

ALVAH W. CLEMENT, OF CLEVELAND, OHIO, ASSIGNOR TO THE CLEVELAND BRASSMANUFACTURING COMPANY OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

'ACID -R ESISTING ALLOY.

To all whom it may concern:

Be it known that I, ALvAH W. CLEMENT. a citizen of the United States,residing at Cleveland, in the county of (uyahoga and State of Ohio, haveinvented a certain new and useful Improvement in Acid-Resisting Alloys,(A,) of which the following is a full. clear, and exact description.

The purpose of this invention is to provide an alloy of metals which ishighly resistant to acids. more particularly sulfuric acid. even thoughthat acid be in a hot diluted condition.

Such an alloy is useful to form contain- ;ers, pumps. pipes and cocks.and other articles by which acid may be handled the same as otherfluids.

The use of an alloy for such purposes, necessitates that the alloy shallbe machinable and that it shall not be brittle.

The principal ingredients of the alloy which is herein proposed areiron, chromium and carbon. which latter element being present as carbidsof iron and chromium.

Small quantities of silicon may be used in fusing the alloy to renderthe fusion more fluid. in order that it may be more easily handled. Thequantity of silicon thus used is small, however, preferably less than 1per cent. and usually varying from to of 1 per cent.

Silicon in such an alloy, has a tendency to throw the carbon presentinto uncombined form, that is to say, as graphitic carbon; thereforecare must be taken that only small quantities be used, as usually thesmall quantities have substantially no effect in this particular.

In order to counteract any tendency for the silicon to throw down thecarbon as graphitic carbon, a. small quantity of manganese may be used,approximately of 1 per cent.

It will be apparent that the quantity of silicon and manganese presentin the alloy is quite small, and so far as the ultimate prop-Spccification of Letters Patent.

Patented Mar. 16, 1920.

Application filed July 26. 1917. Serial No. 182,910.

erties of the alloy so far as acid resistance is concerned, has verylittle, if any effect.

An alloy of pure iron and chromium would not be resistant to the variouscommercial conditions under which sulfuric acid is handled, but an alloyof chromium. iron and carbon, where the carbon exists in the alloy ascarbids of chromium and iron in the proportion of substantially 60 percent. chromium. substantially 39% to 39- per cent. of iron, andsubstantially to per cent. of carbon is to all intents and purposesresistant to all forms of sulfuric or similar acids.

to P of l per cent. of silicon may be added at fusion and just beforepouring. to impart fluidity to the alloy.

Furthermore, such an alloy is machinable. Therefore it is suitable foracid resisting pipes. cocks, and similar devices.

It may be desirable to add to the alloy :1 small amount of molybdenum.cobalt or vanadium. these various substances mentioned, having theproperty of increasing the malleability and ductility of the alloy andthus rendering it easier to machine.

Havingdescribed my invention. what I claim is:

1. An acid resisting metal alloy comprising substantially 60 per cent.of chromium and substantially 39f to 39% per cent. of iron andsubstantially to {1-, per cent. of carbon. the carbon being present as acarbid of chromium and iron.

An acid resisting metal alloy consistingof substantially per cent. ofchr0- mium, substantially 39% per cent. t 39 per cent. of iron vsubstantially to per cent. of carbon which is present as carbids of ironand chromium, and a small amount of an element having the property ofmolybdenum which in'lparts malleability to the alloy.

In testimony whereof, I hereunto afiix my

